The two companies said they have completed the integration of Firefox OS with several of Spreadtrum's WCDMA and EDGE smartphone chipsets.

The first-generation Firefox OS smartphones, which were launched last year by companies such as Alcatel, ZTE, and LG, have been made available primarily through operator channels. Carriers like Telefonica have deployed Firefox OS smartphones, but many analysts see little impact so far on the smartphone market. Scott Bicheno, senior analyst at Strategy Analytics, told us Firefox OS handsets make up "less than 1% of total global smartphone shipments."

The Spreadtrum/Mozilla strategy for $25 smartphones is to change that narrative. Diana Jovin, vice president of corporate strategy at Spreadtrum, told us the devices will be "sold on the open market" and will target "first-time smartphone users."

Worldwide smartphone sales (in thousands of units) to end users by operating system in 2013.(Source: Gartner)

The integration of Firefox OS support into Spreadtrum's smartphone development platform is likely to play a key role. The Chinese vendor's so-called turnkey solution incorporates literally every piece of software and hardware necessary to build a finished handset very quickly, including all the chips, boards, and a display.

A number of Chinese handset ODMs -- with a much better cost structure than Western mobile handset vendors -- are expected to start flooding emerging markets this year with Firefox OS-based entry-level smartphones.

$25 price tag at retail?
That $25 price tag, predictably, has raised a few eyebrows in the analyst community.

Wayne Lam, senior analyst for consumer and communications at IHS, wonders if $25 is the manufacturing cost. "A smartphone has a cost budget that usually looks like 30% for display and 45% for core electronics and 25%" for things like the battery, camera, and enclosures," he told us

When we asked about this, Spreadtrum's Jovin made it clear that $25 is the retail price.

Obviously, a critical element of the price is the low memory configuration of the web-based nature of Firefox's OS. Jovin said a Firefox OS-based smartphone needs just half the memory of other smartphone, which typically require 1 Gbit of embedded DRAM and 2 Gbit of extended NAND.

Lam agreed with that assessment. "FireFox OS has less processing and memory requirements, since the OS and the services live mostly in the cloud. For example, most of the apps written for Firefox OS are written in HTML5 and can be run within a mobile browser."

Spreadtrum unveiled the SC6821 WCDMA smartphone chipset Sunday, Feb. 23, at the Mobile World Congress as the industry's first chipset for $25 smartphones. With this chipset, the company said, handset makers will be able to bring to market smartphones "with 3.5-inch HVGA touchscreens, integrated [with] WiFi, Bluetooth, FM and camera functions, the advanced phone and browser features of Firefox OS, and access to a rich ecosystem of web and HTML5 applications."

It seems Game Over! for the feature phones now. With the smart phones becoming available for such a dirt cheap price who need to stick to those simple phones?

With internet availability on mobiles at affordable rates and with reasonably good bandwidths, and a hoard of cloud based apps , these phones are surely goind to create a storm in the mobile marketplace.

The introduction of low cost smartphones is inevitable. It is time. The challenge of another OS is the limited variety of apps. Windows phone is experiencing the lack of apps and the popularity is limited. How does Mozilla tackle the challenge?

Yes, I also explored the matter little bit, it is all the way a new architecture, and requires a separate binary to be places in Firefox Market Place. So what one can expect is the firmness on the price point, if the FireFox OS bases phone is to be sold at higher than 25$ then it will be a very tough time for them to sell. As that is the only attracting feature for a new buyer.